APPL has the tightest concave curvature followed by arfaptin and then by Amphiphysin/Endophilin and then by Sorting Nexin 9

Amphiphysin (blue) and Endophilin (yellow)

Endophilin (yellow) and Sorting Nexin 9 (magenta)

APPL (light green) and Amphiphysin (blue)

I-BAR comparisons

Comparisons and Overlays of I-BAR structures IRSp53 I-BAR is blue and
MIM I-BAR is yellow. These are compared to Snx9 BAR (in Magenta), showing that the membrane binding interface is the same. While in the BAR domains this inferface is concave, in the I-BARs it is convex.